Some employees raised the alarm shortly after the shift began at 6am and then the lights went out, spreading panic as workers rushed to find an exit, employee Wang Fengya told Xinhua.

"I started working at 6am along with another 100 workers in my workshop. There were two workshops in the plant," said Wang a 44-year-old female worker. She sustained burn injuries while escaping.

"Soon after, someone shouted 'run away!' and we quickly ran to the exit, which is about 40 meters away from my seat. Suddenly, the lights inside went out and the plant got quite dark," Wang said.

State broadcaster CCTV quoted unidentified workers as saying the fire broke out during a change of shifts and may have originated in a locker room at a time when about 350 workers were at the plant.

Jason Yan, technical director of the US Grains Council, in Beijing, told Associated Press that safety considerations usually took a backseat in China to features designed to maximize production and energy efficiency.

"I'm sure they consider some aspects of safety design. However, I think safety, to me, is not the first priority in their design plan," Yan told AP.

Jilin Baoyuanfeng produces 67,000 tons of processed chicken per year and employs about 1,200 people.